Godot is a powerful cross-platform game engine
Solar2D Game Engine main repository (ex Corona SDK)
The flexible game engine
Multi-platform Engine for Desktop, XBOX (UWP) and Mobile games
Multi-platform 2D and 3D game engine
Open source voxel game engine with support for survival and crafting
Xash3D FWGS engine
Cocos simplifies game creation and distribution with Cocos Creator
JavaScript-based game engine designed to empower developers
Flax Engine, multi-platform 3D game engine
Fast and lightweight JavaScript game engine built on WebGL and glTF
Cross-platform 2D and 3D game engine with modular architecture
V1, Mirror Classic. V2, Mirror Engine: Join Discord for access
Cross-Platform C++ 2D/3D game engine
Game engine supporting many 3D/2D formats and graphic effects
A game engine with an emphasis on real-time cutting-edge solutions
Voxel game-creation platform with easy modding and game creation
The game engine for everyone
GemRB is a portable open-source implementation of the Infinity Engine
An OpenGL RTS game engine written in C
Zig game engine & graphics toolkit
Game engine to build text adventures.
Satisfying monster shooter
A dead simple 2D game engine for Go
New Godot bindings for Swift